STEAM GENERATOR DISASSEMBLING METHOD

PROBLEM TO BE SOLVED: To easily disassemble a steam generator at low cost.SOLUTION: A disassembling method for a steam generator 1 includes the processes of: separating an upper trunk 2b from a lower trunk 2a together with a steam separator 9 and a moisture separator 10 with a steam generator 1 stood; and separating a heat transfer pipe 5 and the lower trunk 2b from a pipe plate 4. The steam generator 1 is provided with the pipe plate 4 below a cylindrical trunk part 2 and with a water chamber mirror 7 below the pipe plate 4, many heat transfer pipes 5 formed in an inverted channel shape in the lower trunk 2a of the trunk part 2 are inserted into and supported by a plurality of upper and lower pipe support plates 6 while surrounded with a pipe group outer cylinder 3 to have ends inserted into and fixed to the pipe plate 4 to communicate with water chambers 7A, 7B partitioned in the water chamber mirror 7, and the steam separator 9 and moisture separator 10 are provided in the upper trunk 2b of the trunk part 2.